Great — here are several well-regarded beach resorts in Sri Lanka that specifically offer yoga and broader wellness (Ayurveda, spa, retreats). I’ve included the location, what they offer, and the vibe so you can pick what fits you best.

• Talalla Retreat — Talalla (south coast, near Matara)
  What they offer: multiple open‑air shalas, daily drop‑in yoga, weekly yoga/surf/Pilates retreats, an Ayurvedic spa and a Turkish-inspired “bathhouse” with sauna, steam, cold plunge and red‑light therapy. Vibe: informal, surf‑and‑yoga retreat atmosphere — great for active wellness and retreats. (talallaretreat.com)

• Amanwella — Tangalle (south coast)
  What they offer: beachside open‑air yoga platform, private yoga and meditation sessions (including guided meditation with a monk), in‑suite or beach spa/Ayurvedic treatments and a large oceanfront pool. Vibe: luxury, minimalist, very tranquil — ideal if you want high‑end, quiet wellness. (aman.com)

• Anantara Peace Haven Tangalle (Anantara Tangalle) — Tangalle
  What they offer: Anantara Spa with Ayurvedic treatments, wellness programmes (multi‑day Ayurveda packages), a yoga pavilion with complimentary group yoga by the sea, and private yoga sessions. Vibe: full‑service luxury resort with structured wellness programmes and resort activities. (Anantara.com)

• Barberyn Ayurveda Resorts (Barberyn Beach / Barberyn Waves) — southern coast (Ayurveda focus)
  What they offer: Traditional Ayurveda programmes combined with daily/complimentary yoga and meditation in a large sea‑view yoga pavilion; medically oriented Ayurveda treatment plans and physician consultations. Vibe: Ayurvedic health retreats — excellent if you want authentic, medical Ayurvedic care plus yoga. (barberynresorts.com)

• Cape Weligama — Weligama / south coast
  What they offer: luxury clifftop resort with spa and sea‑facing yoga shala (offers beach/yoga experiences and wellness treatments). Vibe: upscale, design‑forward resort with strong wellness and relaxation offerings. (cntraveller.com)

• Weligama / Mirissa boutique options and surf‑yoga hubs (examples: Basecamp, Green Peace Inn, various surf + yoga retreats)
  What they offer: many smaller beachfront properties and surf hostels that run daily yoga classes, weekend retreats, massages and basic Ayurvedic treatments — often cheaper and more social than big resorts. Vibe: budget to midrange, social, great for combining surf + yoga. (bookyogaretreats.com)

Notes and tips

• Most of these resorts run daily group yoga (sunrise or sunset) plus private lessons and multi‑day wellness packages — but class schedules and programme availability can change seasonally, so check dates before booking.
• If you want medically supervised Ayurveda (dosha consultation, multi‑day treatment plan), choose a dedicated Ayurveda resort (e.g., Barberyn or Anantara’s Ayurvedic programmes). (barberynresorts.com)
• South coast (Tangalle, Weligama, Mirissa, Matara) is the hub for beach yoga + wellness; peak beach season is generally November–April for calm seas and whale watching.

If you’d like, I can:

• Check current retreat dates or sample pricing for any of these properties; or
• Narrow options by exact location, budget, travel dates, or whether you prefer Ayurveda medical programmes vs. casual yoga + spa.